• Authors:
    • Sweeney, D.
    • Kelley, K.
  • Source: Crop Management
  • Issue: July
  • Year: 2010
  • Summary: Field studies were conducted from 1996 through 2006 in southeastern Kansas to evaluate the influence of previous crop [corn, Zea mays L.; grain sorghum, Sorghum bicolor (L.); and soybean, Glycine max (L.) Merr.] and tillage system (conventional versus no-till) on grain yield of hard red winter wheat ( Triticum aestivum L.) and double-crop soybean in a 2-year rotation. On average, wheat yield was greater following corn or soybean than following grain sorghum. Yield of double-crop soybean averaged 20% greater when wheat followed corn or grain sorghum than when wheat followed full-season soybean. Tillage system influenced grain yield of double-crop soybean more than it influenced wheat yield. Double-crop soybean yield often was greater for continuous no-till than for conventional or one-time no-till per cropping cycle. Soil analyses at the end of the study showed that total C and total N were greater for no-till than for conventional in the 0- to 3-inch depth, but total C and total N were greater for conventional than no-till in the 3- to 6-inch depth. In the multi-cropping systems of the eastern Great Plains, both crop rotation and tillage system can significantly influence grain yield and selected soil properties.
  • Authors:
    • Li, L.
    • Du, F.
    • Zhang, F.
    • Zhang, W.
    • Li, H.
  • Source: Plant Nutrition and Fertilizer Science
  • Volume: 16
  • Issue: 5
  • Year: 2010
  • Summary: Since 2004, China has significantly increased its grain production due to the impetus of strong policy support from the government, including soil testing and fertilizer recommendation. This paper analyzes the changes in fertilizer efficiency in China's grain production systems by comparing the farmers' practice in 2008 and 2001. In the period investigated, chemical fertilizer application rate increased by 5.4% and 29.0% in wheat and maize production, respectively, and decreased by 4.3% in rice cultivation. Total fertilizer consumption increased by 1.3 * 10 6 t on grain crops, but its proportion decreased from 68% to 50% in the total chemical fertilizer consumption of the country. PFP (partial factor productivity, i.e. grain yield divided by the amount fertilizer), used to represent the fertilizer use efficiency of rice, was higher than that of wheat and maize. The PFP of wheat and rice increased from 10.6 kg/kg to 11.9 kg/kg and from 13.9 kg/kg to 15.7 kg/kg, respectively, and that of maize decreased from 13.8 kg/kg to 11.5 kg/kg. The change of planting structure had a strong impact on fertilizer application. The concentration of the production of main cereal crops to the areas with advantageous conditions is believed to be good to the improvement of fertilizer efficiency of cereal crops. On the other hand,the continuous increase in the cultivation area of economic crops will bring additional variables to the changing trend of fertilizer efficiency in China.
  • Authors:
    • Manorama, K.
    • Lal, S.
  • Source: Indian Journal of Agronomy
  • Volume: 55
  • Issue: 3
  • Year: 2010
  • Summary: Field trials were conducted on sandy clay loam soils of the Nilgiris during summer seasons of 2003 to 2005 to study the intercropping possibilities of French beans ( Phaseolus vulgaris L), maize ( Zea mays L.) and wheat ( Triticum aestivum L) with potato ( Solanum tuberosum L.) in three population proportions (75:25, 75:50 and 50:50) under rainfed conditions. The results indicated that potato+French bean at 75:50 population recorded significantly higher potato equivalent yield, (PEY) (27.1 t/ha), land equivalent ratio (LER) (1.28) and net returns (Rs 69,090) over sole potato. Intercropping of potato with wheat and maize resulted in significant decrease in PEY over sole potato. Potato is more competitive than other crops as evident from Relative Crowding Coefficient (RCC) values. However, at 50:50 ratios, French bean and maize are more competitive. Potato+maize (75:50 and 50:50) was found soil exhaustive while potato+French bean is soil restorative system.
  • Authors:
    • Armstrong, R.
    • Nuttall, J.
  • Source: Australian Journal of Soil Research
  • Volume: 48
  • Issue: 2
  • Year: 2010
  • Summary: Subsoil physicochemical constraints can limit crop production on alkaline soils of south-eastern Australia. Fifteen farmer paddocks sown to a range of crops including canola, lentil, wheat, and barley in the Wimmera and Mallee of Victoria and the mid-north and Eyre Peninsula of South Australia were monitored from 2003 to 2006 to define the relationship between key abiotic/edaphic factors and crop growth. The soils were a combination of Calcarosol and Vertosol profiles, most of which had saline and sodic subsoils. There were significant correlations between EC e and Cl - ( r=0.90), ESP and B ( r=0.82), ESP and EC e ( r=0.79), and ESP and Cl - ( r=0.73). The seasons monitored had dry pre-cropping conditions and large variations in spring rainfall in the period around flowering. At sowing, the available soil water to a depth of 1.2 m (theta a) averaged 3 mm for paddocks sown to lentils, 28 mm for barley, 44 mm for wheat, and 92 mm for canola. Subsoil constraints affected canola and lentil crops but not wheat or barley. For lentil crops, yield variation was largely explained by growing season rainfall (GSR) and theta a in the shallow subsoil (0.10-0.60 m). Salinity in this soil layer affected lentil crops through reduced water extraction and decreased yields where EC e exceeded 2.2 dS/m. For canola crops, GSR and theta a in the shallow (0.10-0.60 m) and deep (0.60-1.20 m) layers were important factors explaining yield variation. Sodicity (measured as ESP) in the deep subsoil (0.80-1.00 m) reduced canola growth where ESP exceeded 16%, corresponding to a 500 kg/ha yield penalty. For cereal crops, rainfall in the month around anthesis was the most important factor explaining grain yield, due to the large variation in rainfall during October combined with the determinant nature of these crops. For wheat, theta a in the shallow subsoil (0.10-0.60 m) at sowing was also an important factor explaining yield variation. Subsoil constraints had no impact on cereal yield in this study, which is attributed to the lack of available soil water at depth, and the crops' tolerance of the physicochemical conditions encountered in the shallow subsoil, where plant-available water was more likely to occur. Continuing dry seasonal conditions may mean that the opportunity to recharge soil water in the deeper subsoil, under continuous cropping systems, is increasingly remote. Constraints in the deep subsoil are therefore likely to have reduced impact on cereals under these conditions, and it is the management of water supply, from GSR and accrued soil water, in the shallow subsoil that will be increasingly critical in determining crop yields in the future.
  • Authors:
    • Harris, H.
    • Masri, S.
    • Makhboul, R.
    • Pala, M.
    • Singh, M.
    • Ryan, J.
    • Sommer, R.
  • Source: Journal of Agricultural Science
  • Volume: 148
  • Issue: 2
  • Year: 2010
  • Summary: The Mediterranean region is experiencing unrelenting land-use pressure, largely driven by population growth. Long-term cropping system trials can guide crop and soil management options that are biophysically and economically sustainable. Thus, an extensive cereal-based rotation trial (1983-98) was established in northern Syria, to assess various two-course rotations with durum wheat ( Triticum turgidum Desf.). The alternative rotations were: continuous wheat, fallow, chickpea ( Cicer arietinum), lentil ( Lens culinaris), medic ( Medicago spp.), vetch ( Vicia sativa) and watermelon ( Citrullus vulgaris) as a summer crop. Ancillary treatments were: nitrogen (N) fertilizer application to the cereal phase (0, 30, 60 and 90 kg N/ha) and variable stubble grazing management (zero or stubble retention, moderate and heavy grazing). Both phases of the rotation trial occurred each year. The soil is a fine clay, thermic Calcixerollic Xerochrept. Seasonal rainfall was the dominant factor in influencing overall yields. Rotations significantly influenced yields, being highest for fallow (2.43 t/ha), followed by watermelon (similar to fallow), vetch, lentil, medic and chickpea, and least for continuous wheat (1.08 t/ha). Overall, yields increased consistently with added N, but responses varied with the rotation. The various stubble grazing regimes had little or no effect on either grain or straw yields. While the trial confirmed the value of fallow and the drawbacks of continuous cereal cropping, it also showed that replacing either practice with chickpea or lentil, or vetch for animal feed, was potentially a viable option. Given favourable economics, legume-based rotations for food and forage could contribute to sustainable cropping throughout the Mediterranean region.
  • Authors:
    • Morris, C.
    • Scudiero, L.
  • Source: Journal of Cereal Science
  • Volume: 52
  • Issue: 2
  • Year: 2010
  • Summary: Secondary field emission scanning electron microscopy (FE SEM), atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to investigate native near-isogenic soft and hard wheat kernels and their roller milled flours. FE SEM images of flat-polished interior endosperm indicated distinct differences between soft and hard wheats with less internal continuity in the soft wheat, whereas individual starch granules were much less evident in the hard kernel due to a more continuous matrix. AFM images revealed two different microstructures. The interior of the hard kernel had a granular texture with distinct individual spheroid features of 10-50 nm while the images obtained for the soft kernel revealed less distinct small grains and more larger features, possibly micro-structural features of starch granules. Raman spectra resolved identical distinct frequencies for both kernel types with slightly different intensities between types. Finally, the chemical surface compositions of flour for these two types of kernels obtained by XPS provided subtle insight into the differences between soft and hard wheat kernels. These combined advanced microscopic and spectroscopic analyses provide additional insight into the differences between the soft and hard wheat kernels.
  • Authors:
    • Bradford, S.
    • Crohn, D.
    • Poss, J.
    • Shouse, P.
    • Segal, E.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 137
  • Issue: 3/4
  • Year: 2010
  • Summary: A nutrient management plan (NMP) field experiment was conducted to investigate the fate of nitrogen (N), phosphorus (P), potassium (K) and salts in a semi-arid environment (San Jacinto, CA). Our mechanistic approach to study NMP performance was based on comprehensive measurements of water and N mass balance in the root zone. A cereal crop rotation (wheat-rye hybrid to sorghum, Triticum aestivum L.- Secale cereale L. to Sorghum bicolor L. Moench) that does not fix atmospheric N was employed during 2007, whereas a legume crop (alfalfa, Medicago sativa L.) that forms nodules to fix N was used in 2008. Blending (2007 and 2008) and cyclic (2007) dairy wastewater (DWW) application strategies (no statistical difference in 2007) were implemented to meet crop water and N uptake. The high content of salts in DWW and accurate application of water to meet evapotranspiration ( ET) yielded salt accumulation in the root zone. Leaching these salts after the fallow period resulted in the flushing of nitrate that had accumulated in the root zone due to continuous mineralization of soil organic N. This observation suggested that a conservative NMP should account for mineralization of organic N by (i) leaching salts following harvests rather than prior to planting and (ii) maintaining soils with low values of organic N. For the wheat-rye hybrid-sorghum rotation, losses of nitrate below the root zone were minimal and the soil organic N reservoir and P were depleted over time by applying only a fraction of the plant N uptake with DWW (28-48%) and using DWW that was treated to reduce the fraction of organic N (3-10%), whereas K accumulated similar to other salts. Conversely, with alfalfa approximately 15% of the applied N was leached below the root zone and the soil organic N increased during the growing season. These observations were attributed to fixation of atmospheric N, increased root density, and applying a higher fraction of plant N uptake with DWW (76%). Collectively, our results indicate that NMPs should accurately account for water and nutrient mass balances, and salt accumulation to be protective of the environment.
  • Authors:
    • Sundermeier, A.
    • Diedrick, K. A.
    • Dygert, C. E.
    • Mullen, R. W.
    • Henry, D. C.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 1
  • Year: 2010
  • Summary: Inclusion of a winter legume cover crop into a crop rotation has been suggested as a method to provide a substantial portion of the N requirement of the following crop. While the benefits of winter cover crops such as reduced soil erosion, increased soil organic matter, and increased mulch cover have been well documented, the N contribution to the subsequent crop has shown to be variable. The objective of this study was to determine the N contribution from a red clover (Trifolium pratense L.) cover crop following wheat (Triticum aestivum L.) to a subsequent corn (Zea mays L.) crop. The experiment was conducted at two western Ohio locations over 3 yr. At both locations, red clover was either interseeded into wheat or seeded after harvest, the red clover cover crop was eliminated with tillage or herbicide application, and corn was planted with three N rates (0, 90, and 180 kg N ha(-1)). The data revealed that for three of the four site years (when the cover crop was successfully established) there was no N contribution attributable to the presence of red clover. The one site that did show a N contribution revealed that the amount of N contributed was less than 90 kg N ha(-1). However, even when no N benefit was found, yields were improved by non-N-related rotational effects. Significant reductions in N fertilization rates following a red clover cover crop are likely to result in lost corn yield opportunities in western Ohio.
  • Authors:
    • Hucl, P.
    • Matus-Cádiz, M. A.
  • Source: Crop Science
  • Volume: 50
  • Issue: 5
  • Year: 2010
  • Summary: Recent research has addressed the potential for gene flow in wheat (Triticum aestivum L.). However, there is scant information on the fate of introgressed genes in the subsequent crop rotation. The objective of this study was to quantify spring wheat volunteers potentially arising from gene flow. A total of 152 wheat fields that had been used to measure gene flow at distances of up to 10 km were surveyed for blue aleurone volunteers for 3 yr postharvest. No blue aleurone seed was detected in samples from the 152 fields surveyed. A single blue aleurone volunteer plant was detected in a pollen donor field subsequently sown to wheat in the third year postharvest. The absence of blue aleurone wheat volunteers in the postharvest crop rotation was not unexpected as only four of the original 152 fields had shown evidence of gene flow. Under the environmental and crop management practices encountered in this study, the risk of a gene flow-based adventitious event in spring wheat being detected at significant levels in subsequent crops appears low.
  • Authors:
    • Jajoo, S. B.
    • Kambale, P. G.
    • Atal, G. R.
  • Source: Green Farming OR Soil & Water Conservation Engineering
  • Volume: 1
  • Issue: 1
  • Year: 2010
  • Summary: A study was conducted to suggest optimal resources allocation i.e. land and water using linear programming model for Amravati district in Maharashtra State. Considering the land capability classification, availability of water in different seasons, crop water requirements, food requirements of the district, affinity towards the crops and investment capacity of peoples, crop plan was developed to maximize the net return. In existing crop plan during kharif season major area is under cotton (32.41%) followed by soybean (20.19%) whereas in proposed optimal crop plan without capital constraints major area was allocated under soybean (30%), cotton (10%) and jowar (10%) of cultivable area. In rabi major area in existing crop plan is under gram (5.2%) whereas in proposed plan area is allocated to wheat (30%) followed by gram (27%). In existing crop plan gross investment and net return were Rs. 9,268 and Rs. 4,906 per ha where as in proposed plan Rs. 16,057 and Rs. 9,642 per ha. Thus increases net return by Rs. 4,362 by increasing gross investment of Rs. 6,415 per ha.